The Features of Spatial Database Query Languages

Query languages are the most sensitive functions to users. Spatial database query languages should completely supply users with needed data which describe some spatial phenomena. This papaer will give a brief description of the current situation on the spatial database query languages and their main forms. Through analysis of the requirements for spatial database query languages, we boil down, based on characteristics of spatial data and general requirements of query languages, that the query languages must be equipped with the three features:understanding "spatial concepts", descriptive representation of queried results and declarative query process. In the final part of this paper, we outline the main features of three main aspects in spatial database query languages and the key research topics on the query languages in the future.